83781905 has 8 divisors (see below), whose sum is σ = 100698984. Its totient is φ = 66918400.

The previous prime is 83781889. The next prime is 83781911. The reversal of 83781905 is 50918738.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 31494544 + 52287361 = 5612^2 + 7231^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 83781905 - 2⁴ = 83781889 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9866 + ... + 16275.

It is an arithmetic number, because the mean of its divisors is an integer number (12587373).

Almost surely, 2^83781905 is an apocalyptic number.

It is an amenable number.

83781905 is a deficient number, since it is larger than the sum of its proper divisors (16917079).

83781905 is a wasteful number, since it uses less digits than its factorization.

83781905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26787.

The product of its (nonzero) digits is 60480, while the sum is 41.

The square root of 83781905 is about 9153.2455992396. The cubic root of 83781905 is about 437.5725572178.

The spelling of 83781905 in words is "eighty-three million, seven hundred eighty-one thousand, nine hundred five".